Log debarking apparatus



Dec. 19, 1961 3,013,593

C .T. M DONALD LOG DEBARKING APPARATUS Filed Jan. 14, 1960 5 Sheets-Sheet 1 INVENTOR. /Qt/d rM qna/cl BY WW,MY L.

Hf-forn e y.s

Dec. 19, 1961 c T. MCDONALD LOG DEBARKING APPARATUS 3 Sheets-Sheet 2 Filed Jan. 14, 1960 IIVTETWOR. CliuJe IMDonalc/ 7 I M ilmy w HovneyS Dec. 19, 1961 c T. MCDONALD LOG DEBARKING APPARATUS 3 Sheets-Sheet 3 Filed'Jan. 14, 1960 INVENTOR. C la nude E M D Ona'd 3,lll3,593

Patented Dec. 19, 1961 hull.

3,913,593 LOG DEBARKING APPARATUS Claude T. McDonald, 1816 tirestweod Drive, Chattanooga, Tenn. Filed Jan. 14, 196d, Ser. No. 2,592 lit Claims. (Cl. 144-2tl8) This invention relates to log debarking apparatus and more particularly to such apparatus in which the log to be debarked is fed axially and non-rotatively through a rotor having a plurality of angularly spaced bark removing tool units which remove the bark from the log in a helical path.

An object of my invention is to provide a compact ringtype clebarker which shall be simple of construction, economical of manufacture and which shall require a minimum of moving parts, thereby reducing to a minimum the intial cost of the apparatus and the cost of maintaining the apparatus in satisfactory working order.

Another object of my invention is to provide debarking apparatus of the character designated which shall require a minimum of manual controls for operating the same.

A more specific object of my invention is to provide debarking apparatus of the character designated in which a uniform pressure is applied to the bark removing tools, regardless of the diameter of the log being ebarked, by merely adjusting the position of the debarking ring to accommodate logs of various diameters.

Another object of my invention is to provide log debarking apparatus of the character designated in which a uniform pressure is applied to all of the bark removing tools by a single pressure actuating member, thereby eliminating the necessity of separate pressure applying means for each debarking tool.

A further object of my invention is to provide a log debarker of the character designated which eliminates entirely the necessity of mounting fluid pressure operated cylinders within the tool-carrying rotor for applying pressure to the bark removing tools, thus in turn eliminating the necessity of complicated oil seals and the like for such rotating fluid pressure operated cylinders.

Heretofore in the art to which my invention relates, various types of ring debarkers have been devised for feeding logs successively through a ring having debarking tools which rotate around the horizontally conveyed log. However, such apparatus has been unsatisfactory due to the fact that it has required complicated mechanism for applying pressure to the bark removing tools at the ring rotates. Also, no eifective means has been provided for adjusting the pressure applied to the bark removing tools at the diameter of the log being debarked varies in size. The complexity of such apparatus has resulted in high initial cost and has required frequent maintenance and costly repairs to maintain the apparatus in working condition.

To overcome the above and other difficulties, I provide a ring-type debarker in which a single adjustment of the non-rotatable member which carries the debarking ring automatically adjusts the pressure applied to the bark removing tools, whereby the same pressure is applied by the bark removing tools regardless of the size of the log being debarked. That is, the same pressure is applied to the bark removing tools where the apparatus is debarking a small log as where the apparatus is employed to debark a larger log.

Apparatus embodying features of my invention is illus trated in the accompanying drawings, forming a part of this application, in which:

FIG. 1 is a side elevational view of the debarking apparatus, partly broken away;

FIG. 2 is a view taken generally along the line 2-2 'of FIG. 1, partly brokenaway and the driving mechanism for the rotor being omitted for the sake of clarity;

FIG. 3 is a sectional View taken generally along the line 3-3 of FIG. 2, the cable 47 being cut away for the sake of clarity;

FIG. 4 is a fragmental view showing a modified form of my invention in which the wheel members which rotatably support the rotor are provided with grooves for receiving the peripheral edges of the rotor;

FIG. 5 is a fragmental view taken generally along the line 5-5 of FIG. 4;

FIG. 6 is a fragmental view showing the relative position between the bark removing tools and the helical path made by the bark removing tools; and,

FIG. 7 is a view taken generally along the line 7-7 of FIG. 6.

Referring now to the drawings for a better understanding of my invention, I show a supporting frame indicated generally at 10 having upstanding side frame members 11 and 12 at one side thereof and upstanding side frame members 13 and 14 at the other side thereof, as clearly shown in FIG. 3. Mounted for vertical movement relative to the upstanding side frame members is a non-rotatable member indicated generally at 16. The non-rotatable member 16 comprises a pair of spaced vertical plate members 17 and 18 which are connected to each other at the ends thereof by vertical side plates 19 and 23.. The side plates 19 and 21 extend beyond the vertical plates 17 and 13, as shown in FIG. 3, whereby they terminate adjacent the inner surface of the upstanding side frame members 11, 12, 13 and 14, as shown. Secured to the inner surface of the upstanding side frame members 11 and 12 adjacent opposite sides of the vertical side plate I? are vertically extending guide members 22. In

like manner, secured to the inner surface of the up standing side frame members 13 and 14 adjacent opposite sides of the vertical side plates 21 are vertically extending guide members 23.

As shown in FIGS. 2 and 3, the vertical plates 17 and 1a; are provided with a centrally disposed opening 24 therein for receiving a rotor indicated generally at 25. The rotor 25 comprises a pair of spaced annular members 2'6 and 27 which are connected to each other and to a sprocket 28, positioned therebetween, by connector brackets 29', as shown in FIGS. 2 and 3. The sprocket 28 is thus rigidly connected to the annular plates 26 and 27 whereby they rotate as a unit. The sprocket 28 is driven by a suitable power unit, such as a motor 31, through a suitable sprocket and chain assembly which is indicated generally at 32. The peripheral edges of the annular members 26 and 27 are provided with V-shaped grooves 33 therein for receiving angularly spaced wheel members 34 which are mounted for rotation on the vertical side plates 17 and 18 by short shaft members 36. Preferably, the peripheral edges of the wheel member 34 are beveled as at 37 whereby the peripheral edge of the wheel members correspond generally to the peripheral V- shaped grooves 33.

In FIGS. 4 and 5 of the drawings, I show a modified form of my invention in which the annular members of the rotor, indicated at 26 have beveled peripheral edges 33 which are disposed to engage a V-shaped groove 37 provided in wheel members 34* which are positioned angularly about the rotor and are supported by suitable short shafts 36 That is, instead of providing the V- shaped grooves in the periphery of the annular members of the rotor, annular grooves are provided in the wheel members and the peripheral edges of the annular members of the rotorare beveled for engaging the annular groove in the wheel members.

Secured to the annular member 26 of the rotor 25 are a plurality of angularly spaced pivot pins 38 which carry bell-crank levers 39 having arms 41 and 42. The bellcrank levers 39 are adapted for pivotal movement in a plane generally normal to the axis of the rotor 25. Mounted at the free ends of each of the arms 42 is a bark removingtool 43 which is adapted to engage the log being debarked indicated generally at L.

Mounted adjacent the free end of each of the arms 41 is a cable engaging member which is in the form of a double sheave unit 44 having sheaves 4 and 4-4" mounted for rotation on a shaft 46. Passing around the outermost sheave 44 of the sheave units 44- is a resilient cable-like member 47 having one of its ends 48 operatively connected to a piston rod 49 of a fluid pressure operated cylinder 50 which in turn is mounted on frame 10. Fluid under pressure is supplied to and exhausted from the cylinder 50 by suitable conduits in a manner well understood in the art, whereby the piston rod 49 is moved axially of the cylinder 50. The other end 51 of the cable-like member 47 is connected to a rod 52 which is threaded as at 53 for receiving a nut 54. The

rod 52 passes through a suitable opening in a bracket 56 whereby the nut 54 holds the rod 52 at selected positions. I have found that a suitable resilient cable-like member may be formed of a plurality of strands of rubber secured to each other by suitable means. The cable 47 passes around pulleys 55 mounted adjacent the lower portion of the non-rotatable member 16, as shown in FIG. 2. Other pulleys 55 are mounted on the frame 19 in position to be a substantial distance above the pulleys 55 when the member 16 is in its lowermost position, as shown in FIG. 2, whereby the cable 47 is tightened about the sheaves 44 as the member 16 is lowered. That is, upon moving the pulleys 55 downwardly, both ends of the cable 47 are pulled downwardly a substantial distance due to the fact that the ends of the cable 47 extend from the sheave units 44 around pulleys 55 to pulley 55 Ac- I cordingly, for each unit of downward movement of each pulley 55, the adjacent end of cable 47 which passes around sheaves 44 is pulled downward approximately two units. In like manner, for each unit of downward movement of the non-rotatable member 16, the amount of cable take up is approximately two units due to the fact that there are two of the pulleys 55 and the rotor only moves downwardly one unit. It thus follows that for each unit of upward movement of the non-rotatable member 16, the cable 47 is slackened approximately 2 units. Accordingly, upon raising the non-rotatable member 16 to accommodate a larger log L whereby the center of the rotor 25 is in alignment with the center of the larger log, the cable 47 is slackened whereby substantially the same pressure is applied to the bark removing tools 43 as is applied when a smaller log is being debarked. That is, by slackening the resilient cable 47, the debarking tools pivot in a clockwise direction, as viewed in FIG. 2, whereby the bark removing tools 43 are urged by centrifugal force away from the axis of the rotor 25 to accommodate the larger log. The resilient cable 47 applies pressure to the bellcrank lever 39 whereby the bark removing tools carried thereby are urged with the proper pressure into engagement with the log to be debarked. When the non-rotatable member 16 is lowered to accommodate a smaller log, the cable 47 is tightened, whereby uniform pressure is applied to the bark removing tools 43.

Passing around the innermost sheaves 44 of the sheave units 44 is a resilient cable-like member 57 having one of its ends 58 operatively connected to a piston rod 59 of a fluid pressure operated cylinder 61 mounted on frame 10. Fluid under pressure is supplied to and exhausted from the cylinder 61 by suitable means well understood in the art, whereby piston rod 59 is actuated. The other end 62 of the cable 57 is connected to a threaded rod 63, as shown in FIG. 1, which in turn is held in selected positions relative to a stationary bracket 64 by a nut 66. Accordingly, upon raising the nonrotatable member 16 relative to the frame 10, the cable 57 is slackened whereby the bark removing tools move outwardly from the center of rotor 25 by centrifugal force to accommodate a. larger log. On the other hand, when the non-rotatable member 16 is lowered, the cable 57 is tightened, whereby the bark removing tools are urged inwardly toward the center of rotor 25 to accommodate a smaller log, as described hereinabove.

Suitable guide rollers 67 and 68 are provided adjacent the upper end of the non-rotatable member 16 between the ends of the resilient cable 57 whereby the ends of the cable are held in firm engagement with the sheaves of the sheave units 44 as the rotor 25 rotates. In view of the fact that the double sheave units 44 are only provided with sheaves 44 and 44", as shown in FIG. 3, the cable 47 passes around only the top and side sheaves 44 while the cable 57 passes around only the bottom and side sheaves 44 The non-rotatable member 16 is raised and lowered by suitable means, such as a fluid pressure actuated cylinder 76 having a piston rod 77 connected to a yoke-like member 78. The upper end of the non-rotatable member 16 is connected to opposite ends of the yoke-like member 78 by vertically extending rods '79 which are pivotally connected at their lower ends to the non rotatable member by suitable pivot pins 81. Preferably, the upper ends of the rods '79 are threaded as at 32 for receiving adjusting-lock nuts 83, whereby the vertical position of the non-rotatable member 16 may be adjusted.

The log L to be debarked is fed into the opening through the rotor 25 by suitable feed rollers 84 which are driven from a suitable source of power, such as a motor 85, through a sprocket chain assembly indicated generally at 86. Mounted for rotation in suitable bearings adjacent the forward end of the supporting frame is a transverse shaft 87 which carries rearwardly extending holddown arms 88. Mounted for rotation at the rear ends of the hold-down arms 83 is a shaft 89 which carries a hold-down roller 91. The shaft 89 is driven through a suitable sprocket and chain assembly indicated generally at 92. The sprocket and chain assembly 92 is operatively connected to the sprocket chain assembly 86, as shown in FIG. 1.

After being debarked, log L is removed from the rotor 25 by suitable feed rollers 93 which are driven by a suitable sprocket and chain assembly 94 connected to the motor 85. Mounted for rotation adjacent the discharge end of the supporting frame 10 is a transverse shaft 96 which carries forwardly extending hold-down arms 97. Mounted for rotation at the forward end of the holddown arms 97 is a transverse shaft 98 which carries a hold-down roller 99. The shaft 98 is driven by a suitable sprocket and chain assembly indicated generally at 101 which in turn is operatively connected to the sprocket chain assembly 94, as shown in FIG. 1. In view of the fact that various forms of feed apparatus may be employed to pass the log lengthwise through the rotor 25, no further description of the feed mechanism is deemed necessary.

As the log L passes lengthwise through the rotor 25, the rotating bark removing tools 43 remove the bark from the log in a helical path indicated by the dotted lines 102. See FIGS. 6 and.7. The bark removing tool 43 is positioned at an angle relative to the longitudinal center line of the log L whereby it lies in a plane substantially normal to the helical lines 102 defined by the path of the bark removing tools. By so positioning the bark removing tool 43, the cutting edge thereof does not lie in a plane parallel to the grain of the log being debarked, thus pre venting the debarking tool 43 from digging into the log. That is, by positioning the cutting edge of the bark removing tool 43 across the grain of the log being debarked, the cutting edge does not dig into the log as would be the case if the cutting edge of the bark removing tool were in parallel alignment with the grain of the log.

From the foregoing, it will be seen that I have devised an improved ring-type log debarker which is simple of construction and operation. By providing means for auto- U matically adjusting the position of the bark removing tools as the apparatus is adjusted to accommodate logs of various diameters, the same pressure is applied to the bark removing tools regardless of the diameter of the particular log being debarked. Furthermore, by providing the same pressure on all of the bark removing tools, the bark is removed in a uniform and continuous manner.

While I have shown my invention in but two forms, it will be obvious to persons skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. Log debarking apparatus comprising a non-rotatable member having an opening therethrough for passing a log to be debarked, log feed means operable to move a log lengthwise through the opening in said non-rotatable member, means operatively connected to said non-rotatable member operable to move the non-rotatable member into a position whereby the opening therethrough is substantially concentric with the log to be debarked, an annular rotor mounted for rotation in the opening in said non-rotatable member and having a centrally disposed opening through which a log is adapted to move lengthwise, a plurality of angularly spaced bell-crank levers pivotally connected to said rotor for pivotal movement in a plane generally normal to the axis of said rotor, a bark removing tool carried by one arm of each bell-crank lever and positioned inwardly of said rotor whereby upon pivotal movement of the bell-crank levers the bark removing tools more toward and away from the center of the rotor, cable engaging means mounted adjacent the free end of the other arm of each bell-crank lever, a first resilient cable and a second resilient cable passing around and contacting said cable engaging means, with the ends of said first resilient cable extending upwardly from rotor and the ends of said second resilient cable extending downwardly from said rotor, means operatively connecting the ends of said first resilient cable to a stationary support whereby upon moving the non-rotatable member in a direction to accommodate a larger log said first cable is slackened and upon movement of said non-rotatable member in the opposite direction said first cable is tightened, cable guide means mounted on a stationary support adjacent opposite sides of said rotor around which said second resilient cable passes, means operatively connecting the ends of said second resilient cable to a stationary support, and other cable guide means for said second resilient cable mounted on said non-rotatable member in position to be a substantial distance below the first mentioned cable guide means for said second cable while the non-rotatable member is in its lowermost position for receiving a smaller log, whereby upon moving the nonrotatable member in a direction to accommodate a larger log said second resilient cable is slackened and upon movement of said non-rotatable member in the opposite direction said second cable is tightened.

2. Log debarking apparatus as defined in claim 1 in which the cable engaging means comprises a double sheave mounted for rotation adjacent the free end of said other arm of each bell-crank lever.

3. Log debarking apparatus as defined in claim 1 in which the means operable to move the non-rotatable member into a position whereby the opening therethrough is concentric with the log to be debarked comprises a fluid pressure operated cylinder and means operatively connecting said cylinder to said non-rotatable member.

4. Log debarking apparatus as defined in claim 1 in which the rotating bark removing tools engage the longitudinally moving log whereby the bark is removed from the log in a helical path, and the cutting edge of each bark removing tool lies in a plane substantially normal to said helical path.

5. Log debarking apparatus as defined in claim 1 in which at least one end of each of the resilient cables is operatively connected to a fluid pressure operated cylinder whereby the tension applied by the cables to the bark removing tools may be varied.

6. Log debarking apparatus comprising a non-rotatable member having an opening therethrough for passing a log to be debarked, log feed means operable to move a log lengthwise through the opening in said non-rotatable member, means operatively connected to said non-rotatable member operable to move the non-rotatable member into a position whereby the opening therethrough is concentric with the log to be debarked, an annular rotor mounted for rotation within the opening in said nonrotatable member and having a pair of spaced annular members connected to each other by connector brackets, a plurality of angularly spaced Wheel members carried by said non-rotatable member in position to engage the peripheral edges of said spaced annular members whereby the rotor is mounted for rotation relative to said nonrotatable member, said spaced annular members having a centrally disposed opening through which a log is adapted to move lengthwise, a plurality of angularly spaced bell crank levers pivotally connected to one of said spaced annular members for pivotal movement in a plane generally normal to the axis of said rotor, a bark removing tool carried by one arm of each bell-crank lever and positioned inwardly of said rotor whereby upon pivotal movement of the bell-crank levers the bark removing tools move toward and away from the center of the rotor, cable engaging means mounted adjacent the free end of the other arm of each bell-crank lever, a first resilient cable and a second resilient cable passing around and contacting said cable engaging means with the ends of said first resilient cable extending upwardly from said rotor and the ends of said second resilient cable extending downwardly from said rotor, means operatively connecting the ends of said first resilient cable to a stationary support whereby upon moving the non-rotatable member in a direction to accommodate a larger log said first cable is slackened and upon movement of said non-rotatable member in the opposite direction said first cable is tightened, cable guide means mounted on a stationary support adjacent opposite sides of said rotor around which said second resilient cable passes, means operatively connecting the ends of said second resilient cable to a stationary support, and other cable guide means for said second resilient cable mounted on said non-rotatable member in position to be a substantial distance below the first mentioned cable guide means for said second cable while the non-rotatable member is in its lowermost position for receiving a smaller log, whereby upon moving the non-rotatable member in a direction to accommodate a larger log said second cable is slackened and upon movement of said non-rotatable member in the opposite direction said second cable is tightened to apply a constant pressure to the bark removing tools as the non-rotatable member is adjusted to accommodate logs of various diameters.

7. Log debarking apparatus as defined in claim 6 in which the peripheral edges of the spaced annular memhere are provided with grooves therein for receiving the angularly spaced wheel members.

8. Log debarking apparatus as defined in claim 6 in which the wheel members have annular grooves therein for receiving the peripheral edges of the spaced annular members.

9. Log debarking apparatus comprising a non-rotatable member having an opening therethrough for passing a log to be debarked, log feed means operable to move a log lengthwise through the opening in said non-rotatable member, means operatively connected to said non-rotatable member operable to move the non-rotatable member into a position whereby the opening therethrough is concentric with the log to be debarked, an annular rotor mounted for rotation in the opening in said non-rotatable member and having a centrally disposed opening through which a log is adapted to move lengthwise, a plurality of angularly spaced bell-crank levers pivotally connected to said rotor for pivotal movement in a plane generally normal to the axis of said rotor, at burl: removing tool carried by one arm of each bell-crank lever and positioned inwardly of said rotor whereby upon pivotal movement of the bell-crank levers the bark removing tools move toward and away from the center of the rotor, cable engaging means mounted adjacent the free end of the other arm of each bell-crank lever, a cable passing around and contacting said cable engaging means with the ends of said cable extending downwardly from said rotor, cable guide means mounted on a stationary support adjacent opposite sides of said rotor around which said cable passes, means operatively connecting the ends of said cable to a stationary support, and other cable guide means mounted on said non-rotatable member in position to be a substantial distance below the first mentioned cable guide means while the non-rotatable member is in its lowermost position for receiving a smaller log, whereby upon moving the non-rotatable member in a direction to accommodate a larger log said cable is slackened and upon movement of said non-rotatable member in the opposite direction said cable is tightened.

10. Log debarking apparatus comprising a rotary drum through which a log to be debarked passes axially, a plurality of bell-crank levers supported for pivotal movement on said drum to be rotated therewith, a bark removing tool carried by one arm of each bell-crank lever,

a first cable and asecond cable operatively engaging the other arm of each bell-crank lever with the ends of said first cable extending upwardly from said drum and the ends of said second cable extending downwardly from said drum, means operatively connecting the ends of said first cable to a stationary support whereby upon moving the drum upwardly said first cable is slackened and upon movement of said drum downwardly said first cable is tightened, cable guide means mounted on a stationary support adjacent opposite sides of said drum around which said second cable passes, means operatively connecting the ends of said second cable to a stationary support, other cable guide means for said second cable mounted for vertical movement with said drum and positioned a substantial distance below the first mentioned cable guide means for said second cable while said drum is in its lowermost position for receiving a smaller log, whereby upon moving the drum upwardly to accommodate a larger log said second cable is slackened and upon movement of said drum in the opposite direction said second cable is tightened.

References Cited in the file of this patent UNITED STATES PATENTS 2,787,304 Brundell et al. Apr. 2, 1957 2,810,413 Morgan Oct. 22, 1957 2,821,220 Nicholson Jan. 28, 1958 2,843,168 Lunn July 15, 1958 2,904,085 Wennberg Sept. 15, 1959 2,918,952 Searle Dec. 29, 1959 

